Combining successive interference cancellation and carrier sense multiple access in a beam forming IEEE 802.15.4 gateway
10 June 2014
We propose a novel method to maximise the aggregate throughput of an enhanced IEEE 802.15.4 gateway. By exploiting the gateway's beamforming antenna array and successive interference cancellation (SIC) we simultaneously increase range and maximise throughput. Our algorithm organises nodes into clusters, with each cluster assigned a unique spreading code and target gateway receive power. Within a cluster nodes share the medium via CSMA/CA and inter-cluster packet collisions at the gateway are resolved with SIC. Theoretical throughput gains are calculated and then verified with cross layer simulations encompassing ray trace based propagation modelling, IEEE 802.15.4 bit error rate (BER) models, and a discrete event based enhanced MAC simulator. A 4.3x improvement in aggregated throughput is shown in simulations that reflect the theoretical analysis and provide a systematic approach for the throughput optimization.